Hi Sugan
Did you even read the already suggested note https://service.sap.com/sap/support/notes/1913017????
Please find the below extraction from this note, which explains the differences between the basic finish date and the production finish date:
"The basic finish date will be only adjusted if the basic finish date initially calculated is after the requirement date. That generally occurs when basic start date is calculated in the past and system automatically switches to forward scheduling and if the production finish date is less or equal the requirement date. Also, the basic finish date will be adjusted to match the requirement date."
You should read the documentation carefully before asking questions, especially when this documentation has been already referenced on the thread.
BR
Caetano